Electric switch



Aug. 27, 1935. R. M. ARNOLD ET AL ELECTRIC SWITCH 1 Filed March 29,1934

'lNVENTORS- Roam MARNOLD -W11.1.mtI:. NN

2 BY m 'TTQRNEY' Pmmd Aug. 27, 1935' This invention ATENT" orFicE mc'rmc swrrcn Robert m. M and William Lfmm. cum, IIL, a-lgnorI to Oak Manufacturing Company,

spmmss, ms, serialNa'll'lm 1; Claims- (CL sec-u) relates to an electric switch and especiallyto a switch useful for handling minute potentials. In radio receivers of yp having a plurality of. sets of transformers. for use over a plurality of wavebands, it is necessary that suitable switching mechanism be provided to .cut in and out various coils or condensers. Because of the minute potentials and currents, it is essential that the switch provide goodcontact. In addition, it is desirable that the switch be simpie. and cheapto manufacture and not get out of order.

Referringtothedrawing,l"igure 1lsaside viewdaswitch.

Figureilisasectiononlinel-I ofl'igure i. l'igure3isasectiononlineHofPigurel.

' Figure 4 is a detail-of the rotor, while Figures 5 and 8 are detailed views of the stationary contact elements.

4 The switch may have any suitable frame and as illustrated, comprises a pair of rigid plates I and 2, supported in spaced relationship by sleeves Sandi. througheachofthe sleevesisa .bolt l,havinganut ,threadedonthegandthereof. On theopposite ends of sleeves l' and l and over the boltsl,ls apair of switch plates ll and II.

Beyond these plates are small sleeve sections. it, II, it, and II. bridging the spaces betweui plates I. and H andendplates I and 2.

Since mt s p a only one will be described.

It and ii are Plate." is preferably of some rigid insulation m'aterialsuchas interior open region It. Disposed m'i plate ll aroundregioni.

bakelite and is provided with an are a plurality of contact members Ii. These contact members are preferably riveted or eyeleted to plate list 22. contact member Ii has a lug 28 provided with an aperture ll into which any suitable connections may besoldered.

the contactmernber iiares out to form apair of-iaws I and 28. The sides of the laws are preferably tapered. inwardly at It and terminate in a pair of contact edges II and It. The entire contact member ii, is preferably made of some spring" material such as brass or phosphor bronze and because of its resiliency,

tends to keep contact edges 28 and II tightly pressed together:

It will be noted that e contact members II are symmetrically disposed on plate ll so that the contact edges "and II are-tangent to the arcofacircle. -Oertainofthe contact members such as II and and II.

Il may be provided with laws 25 and "which are slightly largerthan the jaws of the other contact members so that the contact edges 28 and 2! of these members extend further in toward the center of the region than the contact mem- 5 hers 2|. The purpose oi this will appear later.

Cooperating with each of the switch plates i0 and II, is,a rotor 36 of rigid insulating material such as bakelite or the like. This rotor has an aperture in the center thereof and a pair of diametrically opposed recesses II and 38. A shaft, 40, is adapted topass through aperture 36 and has the material thereof disto'rted at the rotor so that recesses 31 and II are -fllled by the shaft.

In this way, rotation of shaft ill. will cause rotor It to turn but .will permit the rotor to float on the shaft to some extent.

Rotor it carries a pair of contact plates ll and 42 each one insulated from. the other. These plates have their inner edges 43 cut to clear go shaft and their outer edges form a circle 44. v Each plate it and 42 lag-provided with an outwardly extending tongue 45, the sides of .which are ground to knife edges 48. The two contact plates ll and" are rigidly maintained on rotors tour 44 of the contactplates 4| and 42 and thus remain in contact with one or the other of these plates at all times. This may be'useful m:v

establishing a grouncrconnection.

Tongues I, however, are adapted to cooperate withcontact edges 20 and 29 of the rest of the .35 contact member's 2|. Due to the knife edges of the sides of tongues 45 as well as the shape of laws II and It, tongues I can be rotated to be gripped by any desired set of contact edges 28 Because of the cutting action, and the so tangency oi' the jaw edges, any rotation of shatt ll will cause the contact edges 28 and 29 to bite into the metal of the rotor with both a cutting and sweeping action and thus establish a firm clean contact. The same is true of circular por- 45 tion 44 and'the two contact members 30 and II.

portions are symmetrically disposed in a circle around shaft 40 and pass through this plate; A

spring member 5|, is adapted to be rotated by shaft. 40. Any suitable means may be provided to effect this, such as a pair of wings 52 and 53 provided in shaft 40 and fitting into a pairof slots in spring 5|, this construction being similar to the switch rotor. Spring 5| has its inner end, 55, bent over and locked by wings 56, struck out from shaft 40. The outer end of spring Si is provided with an aperture, which is adapted to maintain a ball bearing 58 struck up portions 50. It is clear that spring 5i will tend to turn shaft 40 so that ball bearing 58 is between two adjacent struck up portions 50 on plate 2. A pair of ears may be struck up from plate 2 in such a way as to act as stops for spring 5|. In order to mount the switch on a panel, a'bushing 65 having a sleeve may be provided.

The above described stop is more fully described and claimed in the copending application of William Major, filed June 22, 1934.

We claim:

1. A switchv comprising a pair of end members in spaced parallel planes, a plurality of insulating stator plates in parallel planes intermediate said end plates, bolts passing through said end index indentations circumferentially arranged, a

shaft in proximity thereto, a series of fixed con- 4 tacts mounted on each stator plate, said contacts being disposed on the circumference of a circle.

concentric with the shaft, said shaft having a non-circular cross-section at least in the regions surrounded by said stator plates, a rotor for each stator plate, said rotor comprising an insulating disc having an aperture therethrough, said aperture being non-circular and similar in crosssection to that of the shaft in proximity to said stator plates, whereby said rotor may be readily moved longitudinally of said shaft but is rotated therewith, a plurality of contacts rigidly secured to said insulating. disc, the contacts on one rotor only being adapted to cooperate with the contacts on one stator only so that in one position certain of said contacts cooperate and when said rotor is turned other contacts cooperate, one set of said series of cooperating contacts being bladelike, while the other'set of -said series of contacts is yoke-shaped and adapted to press on the opposite sides of said bladelike contacts. I

2.'The structure of claim 1, wherein the stator series of contacts is yoke-like and cooperates with the opposite sides of the rotorcontacts. 3. The structure of claim 1, wherein certain of said stator contacts have their active switching surfaces further in toward the shaft than others, whereby a larger contact angle is secured.

4. In an electric switch structure, 'two spaced bases in parallel planes, one of said bases having shaft mounted in said bases, an index spring arm mounted on said shaft'and means for rotatively coupling said shaft and spring arm only when said switch is in its assembled condition, and uncoupling said arm when said index base is moved away from said switch structure preparatory to disassembly.

a. The structure of claim 4, wherein said shaft is composed of at least two portions, one portion having a non-circular cross-section which said spring arm engages during normal assembled position, and another portion of circular cross section which said arm engages when said index base is backed away.

6. An electric switch comprising a front plate having index indentations circumferentially arranged, a rear base parallel to said front base and spaced therefrom, a plurality of flat stator plates disposed in parallel planes between said two base plates and in line therewith, a plurality of bolts passing through said base and stator plates and maintaining them in assembled relation, sleeves over the exposed portions of said bolts between adjacent stator plates and end plates to maintain the members in spaced position, each of said stator plates having an open central region, a plurality of yoke-like stationary contacts circumferentlally arranged on each stator'plate around said open region, a shaft rotatably mounted in said base plates and passing through the open regions in said stator plates,

, a rotor for each stator plate, each rotor comprising an insulating disc and a non-circular aperture centrally disposed thereof through which said shaft passes, at least a portion of said shaft passing through each insulating disc having a cross-section similar to the aperture in said disc whereby said disc is rotatably secured to said shaft but is capable of longitudinal movement, and a plurality of flat contacts mounted on said insulating disc of said rotor and adapted to cooperate with the contacts of a corresponding stator, and a spring arm mounted on said shaft adjacent said front plate rotatably secured to said shaft and adapted to cooperate with said,

index indentations.

7. An electric switch comprising a pair of spaced parallel base plates, at least one fiat stator plate disposed between said base plates and spaced therefrom, bolts passing through said base and stator plates,'sleeves surrounding the exsaid plates in spaced relationship, said stator plate having an interior open region, a plurality of fixed contacts circumferentially arranged on said stator plate around said open region, ,a round shaft rotatably secured in said two base plates, a rotor comprising a flat disc carrying a.

plurality of contacts mounted on said shaft, said rotor being adapted to cooperate with said stator, said rotor having a circumferential aperposed portions of said bolts only, maintaining ture through which saidshaft passes, and at least one notch cut in said rotor atthe circumference of said aperture and at least one protuberance indentations.

9. The switch of claim 1 wherein said stator contacts each comprise a doubled strip of spring metal having a body portion for mounting on said stator, a connectingportion extending from one side of said body portion awayfrom said shaft and adapted to have wires soldered thereto, and a contacting portion extending from the opposite side of the body portion in toward said shaft, said conifectlng and body portions having, the two thicknesses 01' metal in contacting relation, said contacting portion having the two metal layers bent away from each otherwith their tree edges turned toward and opposite each other and adapted to grip the movable contact therebetween.

10PM electric switch comprising-a rotor having a pluralityot flat contacts thereon adapted to be moved in their own plane. a stator having a plurality of contacts mounted thereon, each contact comprising'a doubled strip. of spring 7 metal forming a body portion for mounting on said stator, a connecting portion extending from said body portion at one side thereof, said body and connecting portions having the two thicknesses of metal pressed together and a contacting portion extending from said body portion at the other side, said contacting portion having the two strips of spring metal bent outwardly from each other with their free edges approaching each other on opposite sides of said rotor to form a knife edge contact on both sides of said movable contact.

'11. A multi-section switchcomprising a plurality of insulating stator disks each or said disks movable a1 tatively moimting said-shattso that it through the centralapertures-oi said shaft havinga non-circular cross section at at the portions thereof. each a rotor disk 0! insulating material tor each oi! the stator disks, a seriu of contacts carried by FEE eachxrotor disk. each rotor disk having a noncircular aperture tothe cross section or the shaft whereby each rotor disk is retatively'sec d to said shaft but is transversely 'saidshafttoadiustitselitoirregularities in the alignment of said stator disks,

said stationary and movable contacts cooperating so that as said rotor disksare turned aswitching action is obtained. a 1

12. The switch or claim 11 wherein an end plate is provided throimh which said bolts pass, saidend plate having an indexing means including an arm having a non-circular aperture through which said shaft passes, said shaft having anoncircular cross section to rotatively engage. said arm.

13. The switch 0! claim 11 wherein one oi! said two series of cooperating contacts of each switching section includes means for maintaining the stator and rotor disks of each section in coopera tive relationship whereby when said shalt is withdrawn from a section, each switching section will remain in place.

ROBERT M: ARNOLD. so 

